Self-healing thermal interface materials

ABSTRACT

A self-healing thermal interface material includes a reactive silicone-based material and a thermally conductive filler material. The reactive silicone-based material is modified to include one or more hydrogen bonding functional groups. The thermally conductive filler material is modified to include a thymine functional group or an adenine functional group.

BACKGROUND

Thermal interface materials are used to couple a heat generating device(e.g., a die or a lidded die) to a heat sink or a cold plate. Thermalinterface materials are available in several forms, including a gel, apaste, a pad, or a grease. Very thin bond lines can be achieved withpastes and/or gels and are, therefore, favored for those applicationswhere high heat loads need to be dissipated from the chip or die. Oneproblem associated with the paste or gel, however, is thermal “pumping”that occurs during power cycling. That is, system power results in thecomponents heating up and subsequently expanding and reducing the bondline. With system power off, components cool and contract, and the bondline increases. The net result of this cyclic expansion/contraction isthat the thermal interface material is pumped out of the bond line,resulting in air gaps or voids, which are detrimental to systemperformance. Consequently, the advantages of using a gel or greasethermal interface material are offset by this degradation inperformance.

SUMMARY

According to an embodiment, a self-healing thermal interface material isdisclosed. The self-healing thermal interface material includes areactive silicone-based material and a thermally conductive fillermaterial. The reactive silicone-based material is modified to includeone or more hydrogen bonding functional groups.

According to another embodiment, a self-healing thermal interfacematerial is disclosed that includes a silicone-based material, a firstthermally conductive filler material and a second thermally conductivefiller material. The first thermally conductive filler material ismodified to include a thymine functional group, and the second thermallyconductive filler material is modified to include an adenine functionalgroup.

According to another embodiment, a process of forming a self-healingthermal interface material is disclosed. The process includes modifyinga reactive silicone-based material to include one of more hydrogenbonding functional groups. The process also includes forming a blendthat includes the modified reactive silicone-based material and athermally conductive filler material. The process further includesforming a self-healing thermal interface material that includes theblend.

The foregoing and other objects, features, and advantages of theinvention will be apparent from the following more particulardescriptions of exemplary embodiments of the invention as illustrated inthe accompanying drawings wherein like reference numbers generallyrepresent like parts of exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an apparatus that includes a self-healingthermal interface material of the present disclosure disposed between aheat generating device and a heat dissipating device, according to oneembodiment.

FIG. 2 is a chemical reaction diagram illustrating a process ofmodifying a reactive silicone material to incorporate functional groupsthat allow for hydrogen bonding, according to one embodiment.

FIG. 3 is a chemical reaction diagram illustrating a process of forminga blend that includes a first reactive silicone material that ismodified to include a first functional group and a second reactivesilicone material that is modified to include a second functional groupin order to allow for hydrogen bonding, according to one embodiment.

FIG. 4 is a diagram illustrating a process of modifying a thermallyconductive filler material with a functional group that allows foradditional hydrogen bonding, according to one embodiment.

FIG. 5 is a diagram illustrating a process of bonding a functional groupto the modified thermally conductive filler material of FIG. 4,according to one embodiment.

FIG. 6 is a diagram illustrating a process of bonding a functional groupto the modified thermally conductive filler material of FIG. 4,according to one embodiment.

FIG. 7 is a diagram illustrating a process of blending the modifiedthermally conductive filler material of FIG. 5 with the modifiedthermally conductive filler material of FIG. 6 to allow for hydrogenbonding of the two functional groups, according to one embodiment.

FIG. 8 is a diagram illustrating a process of blending the modifiedthermally conductive filler material of FIG. 5 with the modifiedsilicone-based material depicted at the top of FIG. 3 to allow forhydrogen bonding of the two functional groups, according to oneembodiment.

FIG. 9 is a diagram illustrating a process of blending the modifiedthermally conductive filler material of FIG. 6 with the modifiedsilicone-based material depicted at the bottom of FIG. 3 to allow forhydrogen bonding of the two functional groups, according to oneembodiment.

FIG. 10 is a flow diagram showing a particular embodiment of a processof forming a self-healing thermal interface material that includes ablend of a modified silicone-based material and a thermally conductivefiller material.

FIG. 11 is a flow diagram showing a particular embodiment of a processof forming a self-healing thermal interface material that includes ablend of a modified thermally conductive filler material and a modifiedsilicone-based material.

DETAILED DESCRIPTION

The present disclosure describes self-healing thermal interfacematerials and methods of forming self-healing thermal interfacematerials. The self-healing thermal interface materials of the presentdisclosure may be generated using thermally conductive filler materialswhich are blended into a silicone-based material that affords theability to self-heal when cracking or voiding occurs via functionalgroups that have been attached to the silicone. The silicone-basedmaterials of the present disclosure include reactive silicones that aremodified to incorporate functional groups that, when in contact witheach other, allow for hydrogen bonding. Hydrogen bonding between thefunctional groups enables the thermal interface material to “self-heal”itself as it undergoes thermal pumping.

As described further herein, examples of hydrogen bonding functionalgroups include adenine functional groups and thymine functional groups.In some cases, the hydrogen bonding functional groups may beincorporated into a single modified reactive silicone material that maybe blended with conductive fillers to generate the self-healing thermalinterface materials of the present disclosure. In other cases, onefunctional group (e.g., an adenine functional group) may be incorporatedinto a first modified reactive silicone-based material, and acorresponding functional group (e.g., a thymine functional group) may beincorporated into a second modified reactive silicone-based material.Alternatively, a modified reactive silicone material may be blended witha thermally conductive filler material that has been modified with afunctional group that allows for additional hydrogen bonding. While thepresent disclosure describes adenine and thymine as examples offunctional groups that allow for hydrogen bonding, it will beappreciated that alternative hydrogen bonding moieties may be utilized.

Referring to FIG. 1, a diagram 100 illustrates an example of anapparatus that includes a self-healing thermal interface material 102disposed between a heat generating device 104 (e.g., a die or a liddeddie) and a heat dissipating device 106 (e.g., a heat sink or a coldplate). As described further herein, the self-healing thermal interfacematerial 102 depicted in FIG. 1 may include thermally conductive fillerswhich are blended into a silicone-based material that affords theability to self-heal when cracking or voiding occurs via functionalgroups that have been attached to the silicone material. For example,the silicone-based materials of the present disclosure include reactivesilicones that are modified to incorporate functional groups that, whenin contact with each other, allow for hydrogen bonding. Hydrogen bondingbetween the functional groups enables the thermal interface material to“self-heal” itself as it undergoes thermal pumping.

In one embodiment, the self-healing thermal interface material 102 ofFIG. 1 may include a thermally conductive filler material (e.g.,alumina) that includes the silicone-based material that includes twofunctional groups as depicted in FIG. 2. In another embodiment, theself-healing thermal interface material 102 of FIG. 1 may include athermally conductive filler material (e.g., alumina) that includes theblend of the modified silicone-based materials depicted in FIG. 3. Inanother embodiment, the self-healing thermal interface material 102 ofFIG. 1 may include the blend of modified thermally conductive fillermaterials depicted in FIG. 7 (along with a modified or non-modifiedsilicone-based material). In a further embodiment, the self-healingthermal interface material 102 of FIG. 1 may include the blend ofmaterials depicted in FIG. 8. In yet another embodiment, theself-healing thermal interface material 102 of FIG. 1 may include theblend of materials depicted in FIG. 9.

Referring to FIG. 2, a chemical reaction diagram 200 illustrates aparticular embodiment of a process of modifying a reactive siliconematerial to incorporate functional groups that allow for hydrogenbonding. As described further herein, the resultant material depicted inFIG. 2 may be blended with thermally conductive filler material(s) suchas alumina to generate a self-healing thermal interface material.

In the reactive silicone material of FIG. 2, the integer m is used todesignate portions of the silicone polymer backbone where hydrogenschemically react with the adenine functional group material toincorporate the adenine functionality into the polymer backbone, and theinteger n is used to designate portions of the silicone polymer backbonewhere hydrogens chemically react with the thymine functional groupmaterial to incorporate the thymine functionality into the polymerbackbone.

In the particular embodiment illustrated in FIG. 2, the adeninefunctional group material (depicted at the top of FIG. 2) is9-(4-vinylbenzyl)-9H-purin-6-amine. In other embodiments, alternativeand/or additional materials that include adenine functional groups maybe utilized. In the particular embodiment illustrated in FIG. 2, thethymine functional group material (depicted at the bottom of FIG. 2) is5-methyl-1-(4-vinylbenzyl)pyrimidine-2,4(1H,3H)-dione. In otherembodiments, alternative and/or additional materials that includethymine functional groups may be utilized. FIG. 2 further illustratesthat a catalyst such as platinum (Pt) may be utilized to bond thefunctional group materials to the silicone polymer backbone. The rightside of the chemical reaction diagram of FIG. 2 illustrates that theresultant product includes both adenine functional groups and thyminefunctional groups bound to the silicone polymer backbone.

FIG. 2 depicts an example in which the reactive silicone material ischemically reacted with a blend of the adenine functional group materialand the thymine functional group material. In other cases, theindividual chemical reactions may be performed separately, with lowconcentration to ensure selective reaction with available hydrogens. Asan example, the reactive silicone material may be reacted with a lowconcentration of the adenine functional group material, followed bychemical reaction of the resultant product with the thymine functionalgroup material. As another example, the reactive silicone material maybe reacted with a low concentration of the thymine functional groupmaterial, followed by chemical reaction of the resultant product withthe adenine functional group material.

Thus, FIG. 2 illustrates an example of a process of forming afunctionalized silicone-based material that includes two functionalgroups bonded to a polymer chain of a reactive silicone material. Whenin contact, the two functional groups (e.g., adenine and thyminefunctional groups) allow for hydrogen bonding. As described furtherherein, the ability of the functional groups to form hydrogen bondsallows the resultant product depicted in FIG. 2 to be utilized as acomponent of a self-healing thermal interface material.

Referring to FIG. 3, a chemical reaction diagram 300 illustrates aparticular embodiment of a process of forming a blend that includes afirst reactive silicone material that includes a first functional groupand a second reactive silicone material that includes a secondfunctional group in order to allow for hydrogen bonding. In the firstchemical reaction depicted at the top of FIG. 3, the reactive siliconematerial is chemically reacted with an adenine functional groupmaterial. In the second chemical reaction depicted at the bottom of FIG.3, the reactive silicone material is chemically reacted with a thyminefunctional group material. Blending the two materials together allowsfor hydrogen bonding between the adenine functional groups and thethymine functional groups. As described further herein, the hydrogenbonding may allow the blend depicted in FIG. 3 to be utilized as acomponent of a self-healing thermal interface material.

The first chemical reaction depicted at the top of FIG. 3 illustratesthe modification of a reactive silicone-based material with an adeninefunctional group to form a first modified silicone-based material thatincludes the adenine functional group bonded to the silicone polymerbackbone. In the particular embodiment illustrated in FIG. 3, theadenine functional group material (depicted at the top of FIG. 3) is9-(4-vinylbenzyl)-9H-purin-6-amine. In other embodiments, alternativeand/or additional materials that include adenine functional groups maybe utilized. FIG. 3 further illustrates that a catalyst such as platinum(Pt) may be utilized to bond the adenine functional group material tothe silicone polymer backbone. The right side of the first chemicalreaction diagram of FIG. 3 illustrates that the resultant productincludes adenine functional groups bound to the silicone polymerbackbone.

The second chemical reaction depicted at the bottom of FIG. 3illustrates the modification of a reactive silicone-based material witha thymine functional group to form a second modified silicone-basedmaterial that includes the thymine functional group bonded to thesilicone polymer backbone. In the particular embodiment illustrated inFIG. 3, the thymine functional group material (depicted at the bottom ofFIG. 3) is 5-methyl-1-(4-vinylbenzyl)pyrimidine-2,4(1H,3H)-dione. Inother embodiments, alternative and/or additional materials that includethymine functional groups may be utilized. FIG. 3 further illustratesthat a catalyst such as platinum (Pt) may be utilized to bond thefunctional group materials to the silicone polymer backbone. The rightside of the second chemical reaction diagram of FIG. 3 illustrates thatthe resultant product includes thymine functional groups bound to thesilicone polymer backbone.

FIG. 3 further illustrates that the first modified silicone-basedmaterial that includes the adenine functional group bonded to thesilicone polymer backbone (depicted at the top of FIG. 3) may be blendedwith the second modified silicone-based material that includes thethymine functional group bonded to the silicone polymer backbone(depicted at the bottom of FIG. 3). As described further herein, theblend of the resultant materials depicted in FIG. 3 may be blended withthermally conductive filler material(s) such as alumina to generate aself-healing thermal interface material.

Thus, FIG. 3 illustrates an example of a process of forming a blend thatincludes a first reactive silicone material that includes a firstfunctional group (e.g., an adenine functional group) and a secondreactive silicone material that includes a second functional group(e.g., a thymine functional group) in order to allow for hydrogenbonding. As described further herein, the ability of the functionalgroups to form hydrogen bonds allows the blend depicted in FIG. 3 to beutilized as a component of a self-healing thermal interface material.

Referring to FIG. 4, a diagram 400 illustrates a process of modifying athermally conductive filler material with a functional group that allowsfor additional hydrogen bonding. In a particular embodiment, thethermally conductive filler material of FIG. 4 includes alumina. Inother cases (e.g., in the case of a silicone-base caulk), the thermallyconductive filler material may include a silica particle.

FIG. 4 illustrates that a chemical reaction of the thermally conductivefiller material (e.g., alumina) with a chlorosilane results in theformation of the modified thermally conductive filler material depictedon the right side of FIG. 4. As described further herein with respect toFIGS. 5-9, the modified thermally conductive filler material of FIG. 4may represent a component of a blend of materials that may be utilizedas a self-healing thermal interface material (e.g., the self-healingthermal interface material 102 of FIG. 1).

Referring to FIG. 5, a diagram 500 depicts an example of a process ofbonding a functional group to the modified thermally conductive fillermaterial of FIG. 4. In some cases, as illustrated and further describedherein with respect to FIG. 7, the resultant material of FIG. 5 may beblended with the resultant material of FIG. 6 in order to allow forhydrogen bonding between the two functional groups. In other cases, asillustrated and further described herein with respect to FIG. 8, theresultant material of FIG. 5 may be blended with the resultant materialdepicted at of the top of FIG. 3 in order to allow for hydrogen bondingbetween the two functional groups.

Referring to FIG. 6, a diagram 600 depicts an example of a process ofbonding a functional group to the modified thermally conductive fillermaterial of FIG. 4. In some cases, as illustrated and further describedherein with respect to FIG. 7, the resultant material of FIG. 6 may beblended with the resultant material of FIG. 5 in order to allow forhydrogen bonding between the two functional groups. In other cases, asillustrated and further described herein with respect to FIG. 9, theresultant material of FIG. 6 may be blended with the resultant materialdepicted at of the bottom of FIG. 3 in order to allow for hydrogenbonding between the two functional groups.

Referring to FIG. 7, a diagram 700 illustrates a process of blending themodified thermally conductive filler material of FIG. 5 with themodified thermally conductive filler material of FIG. 6 to allow forhydrogen bonding of the two functional groups, according to oneembodiment. The blend depicted in FIG. 7 may then be blended into anon-modified or modified silicone-based material to form theself-healing thermal interface material 102 of FIG. 1.

Referring to FIG. 8, a diagram 800 illustrates a process of blending themodified thermally conductive filler material of FIG. 5 with themodified silicone-based material depicted at the top of FIG. 3 to allowfor hydrogen bonding of the two functional groups, according to oneembodiment.

Referring to FIG. 9, a diagram 900 illustrates a process of blending themodified thermally conductive filler material of FIG. 6 with themodified silicone-based material depicted at the bottom of FIG. 3 toallow for hydrogen bonding of the two functional groups, according toone embodiment.

Referring to FIG. 10, a flow diagram illustrates an exemplary process1000 of forming a self-healing thermal interface material, according toa particular embodiment. As described further herein, the self-healingthermal interface materials of the present disclosure may be generatedusing thermally conductive filler materials which are blended into asilicone-based material that affords the ability to self-heal whencracking or voiding occurs via functional groups that have been attachedto the silicone. The silicone-based materials of the present disclosureinclude reactive silicones that are modified to incorporate functionalgroups that, when in contact with each other, allow for hydrogenbonding. Hydrogen bonding between the functional groups enables thethermal interface material to “self-heal” itself as it undergoes thermalpumping.

The process 1000 includes modifying a reactive silicone material toinclude one or more hydrogen bonding functional groups, at 1002. Forexample, referring to FIG. 2, the reactive silicone material may bechemically reacted with the blend of adenine functional group materialand thymine functional group material to form the modifiedsilicone-based material that includes both the adenine functional groupand the thymine functional group. As another example, referring to FIG.3, the reactive silicone material may be chemically reacted with anadenine functional group material (depicted at the top of FIG. 3), andthe reactive silicone material may be chemically reacted with a thyminefunctional group material (depicted at the bottom of FIG. 3). As shownin FIG. 3, the resulting modified materials may be used to form a blendthat includes a first modified silicone-based material and a secondmodified silicone-based material.

The process 1000 includes forming a blend that includes the modifiedsilicone-based material and a thermally conductive filler material, at1004. For example, the modified silicone-based material of FIG. 2 may beblended with a thermally conductive filler material (e.g., alumina). Asanother example, the blend of the modified silicone-based materials ofFIG. 3 may be blended with a thermally conductive filler material (e.g.,alumina).

The process 1000 includes forming a self-healing thermal interfacematerial that includes the blend, at 1006. For example, the modifiedsilicone-based material of FIG. 2 that includes both the adeninefunctional group and the thymine functional group may be used as acomponent of the self-healing thermal interface material 102 depicted inFIG. 1. As another example, referring to FIG. 3, a blend that includesthe first modified silicone-based material that includes the adeninefunctional group and the second modified silicone-based material thatincludes the thymine functional group may be used to form a component ofthe self-healing thermal interface material 102 depicted in FIG. 1.

Thus, FIG. 10 illustrates an example of a process of forming aself-healing thermal interface material. The self-healing thermalinterface material formed according to the process depicted in FIG. 10may include modified silicone-based materials that include functionalgroups that allow for hydrogen bonding between the functional groupssuch that the thermal interface material may “self-heal” itself as itundergoes thermal pumping.

Referring to FIG. 11, a flow diagram illustrates an exemplary process1100 of forming a self-healing thermal interface material, according toa particular embodiment. As described further herein, the self-healingthermal interface materials of the present disclosure may be generatedusing thermally conductive fillers which are blended into asilicone-based material that affords the ability to self-heal whencracking or voiding occurs via functional groups that have been attachedto the silicone. The silicone-based materials of the present disclosureinclude reactive silicones that are modified to incorporate functionalgroups that, when in contact with each other, allow for hydrogenbonding. Hydrogen bonding between the functional groups enables thethermal interface material to “self-heal” itself as it undergoes thermalpumping.

The process 1100 includes modifying a thermally conductive fillermaterial to form a modified thermally conductive filler material, at1102. The modified thermally conductive filler material includes ahydrogen bonding functional group (e.g., an adenine functional group ora thymine functional group). For example, referring to FIG. 4, thethermally conductive filler material (e.g., alumina) may be chemicallyreacted with a chlorosilane material to form the modified thermallyconductive filler material. In some cases, as shown in FIG. 5, themodified thermally conductive filler material of FIG. 4 may be modifiedwith a thymine functional group. In other cases, as shown in FIG. 6, themodified thermally conductive filler material of FIG. 4 may be modifiedwith an adenine functional group.

The process 1100 includes modifying a reactive silicone material toinclude a hydrogen bonding functional group, at 1104. For example,referring to the chemical reaction depicted at the top of FIG. 3, thereactive silicone material may be chemically reacted with an adeninefunctional group material to form the first modified silicone-basedmaterial. As another example, referring to the chemical reactiondepicted at the bottom of FIG. 3, the reactive silicone material may bechemically reacted with a thymine functional group material to form thesecond modified silicone-based material.

The process 1100 includes forming a self-healing thermal interfacematerial that includes the modified thermally conductive filler materialand the modified reactive silicone material, at 1106. For example,referring to FIG. 7, the modified thermally conductive filler materialof FIG. 5 (including a thymine functional group) and the modifiedthermally conductive filler material of FIG. 6 (including an adeninefunctional group) may be blended with a modified or non-modifiedsilicone based-based material and utilized to form the self-healingthermal interface material 102 of FIG. 1. As another example, themodified thermally conductive filler material of FIG. 8 (including thethymine functional group) may be blended with the modified reactivesilicone material depicted at the top of FIG. 3 (including the adeninefunctional group) to form the self-healing thermal interface material102 of FIG. 1. As a further example, the modified thermally conductivefiller material of FIG. 9 (including the adenine functional group) maybe blended with the modified reactive silicone material depicted at thebottom of FIG. 3 (including the thymine functional group) to form theself-healing thermal interface material 102 of FIG. 1.

Thus, FIG. 11 illustrates an example of a process of forming aself-healing thermal interface material. The self-healing thermalinterface material formed according to the process depicted in FIG. 11may include modified silicone-based materials that include functionalgroups that allow for hydrogen bonding between the functional groupssuch that the thermal interface material may “self-heal” itself as itundergoes thermal pumping.

It will be understood from the foregoing description that modificationsand changes may be made in various embodiments of the present inventionwithout departing from its true spirit. The descriptions in thisspecification are for purposes of illustration only and are not to beconstrued in a limiting sense. The scope of the present invention islimited only by the language of the following claims.

What is claimed is:
 1. A self-healing thermal interface materialcomprising: a reactive silicone-based material that is modified toinclude one or more hydrogen bonding functional groups; and a thermallyconductive filler material that is modified to include a thyminefunctional group or an adenine functional group.
 2. The self-healingthermal interface material of claim 1, wherein the one or more hydrogenbonding functional groups include at least one of a thymine functionalgroup or an adenine functional group.
 3. The self-healing thermalinterface material of claim 2, wherein the reactive silicone-basedmaterial is modified to include the adenine functional group and thethymine functional group.
 4. The self-healing thermal interface materialof claim 1, wherein the reactive silicone-based material includes ablend of modified silicone-based materials, the blend of modifiedsilicone-based materials including a first silicone-based material thatis modified to include a thymine functional group and a secondsilicone-based material that is modified to include an adeninefunctional group.
 5. The self-healing thermal interface material ofclaim 1, wherein the thermally conductive filler material includesalumina.
 6. The self-healing thermal interface material of claim 1,wherein the thermally conductive filler material is modified to includethe thymine functional group, and wherein the reactive silicone-basedmaterial is modified to include the adenine functional group.
 7. Theself-healing thermal interface material of claim 1, wherein thethermally conductive filler material is modified to include the adeninefunctional group, and wherein the reactive silicone-based material ismodified to include the thymine functional group.
 8. A self-healingthermal interface material comprising: a silicone-based material; afirst thermally conductive filler material that is modified to include athymine functional group; and a second thermally conductive fillermaterial that is modified to include an adenine functional group.
 9. Theself-healing thermal interface material of claim 8, wherein the firstthermally conductive filler material is formed via a chemical reactionof a silicon hydride modified alumina material and a thymine functionalgroup material.
 10. The self-healing thermal interface material of claim9, wherein the thymine functional group material includes5-methyl-1-(4-vinylbenzyl)pyrimidine-2,4(1H,3H)-dione.
 11. Theself-healing thermal interface material of claim 8, wherein the secondthermally conductive filler material is formed via a chemical reactionof a silicon hydride modified alumina material and an adenine functionalgroup material.
 12. The self-healing thermal interface material of claim11, wherein the adenine functional group material includes9-(4-vinylbenzyl)-9H-purin-6-amine.
 13. A process of forming aself-healing thermal interface material, the process comprising:modifying a reactive silicone-based material to include one or morehydrogen bonding functional groups; forming a blend that includes themodified reactive silicone-based material and a thermally conductivefiller material that is modified to include a thymine functional groupor an adenine functional group; and forming a self-healing thermalinterface material that includes the blend.
 14. The process of claim 13,wherein the one of more hydrogen bonding functional groups include atleast one of a thymine functional group or an adenine functional group.15. The process of claim 14, wherein the modified reactivesilicone-based material includes the thymine functional group and theadenine functional group.
 16. The process of claim 14, wherein themodified reactive silicone-based material includes a blend of modifiedreactive silicone-based materials, the blend including a first modifiedsilicone-based material that includes a thymine functional group and asecond modified silicone-based material that includes an adeninefunctional group.
 17. The process of claim 16, wherein: the firstmodified silicone-based material is formed by chemically reacting thereactive silicone-based material with5-methyl-1-(4-vinylbenzyl)pyrimidine-2,4(1H,3H)-dione.
 18. The processof claim 13, wherein the modified reactive silicone-based materialincludes a thymine functional group, and wherein the thermallyconductive filler material is modified to include an adenine functionalgroup.
 19. The process of claim 13, wherein the modified reactivesilicone-based material includes an adenine functional group, andwherein the thermally conductive filler material is modified to includea thymine functional group.
 20. The process of claim 16, wherein thesecond modified silicone-based material is formed by chemically reactingthe reactive silicone-based material with9-(4-vinylbenzyl)-9H-purin-6-amine.